1. Field of the Invention
The invention relates generally to a process for reducing the oxygen content of high-oxygen feedstocks, and more particularly to the conversion of bio-oil components to hydrocarbon fuels.
2. Description of the Related Art
Increasingly, renewable resources are being studied as replacements for fossil fuels. In particular biomass materials are being looked at as a source for liquid fuels for internal combustion engines.
Liquid fuels obtained from crude oil consist predominantly of hydrocarbons and aromatics. The constituents are almost exclusively carbon (C), and hydrogen (H), and little or no oxygen. Conversion products from biomass invariably comprise significant amounts of oxygen. Ligno-cellulosic biomass and bio-oils derived therefrom typically have an oxygen content of at least 20% by weight, and sometimes as high as 50% by weight. The energy content of these materials is accordingly much lower than that of fossil fuels.
It is necessary to upgrade biomass-derived fuels by reducing their oxygen content. Techniques that have been proposed thus far include cracking, for example fluid catalytic cracking (FCC); hydro-cracking; hydro-treating; and hydro-deoxygenation. What these techniques have in common is that much of the oxygen removal relies on the reaction of oxygen with hydrogen to form water. The hydrogen is either supplied externally, or is consumed from the biomass feedstock. Externally supplied hydrogen is expensive, and adds significantly to the cost of biomass-derived fuels. If no external hydrogen is supplied the hydrogen content of the biofuel is reduced during the cracking process, which lowers the energy content of the fuel.
Thus, there is a particular need for a process for reducing the oxygen content of a high-oxygen feedstock that has a reduced hydrogen consumption as compared to existing processes.
There is a further need for a process that may be carried out in existing plant available in oil refineries.